<template>
  <div>
    <p>{{ title }}</p>
    <button @click="fn">change</button>
  </div>
</template>

<script>
export default {
  name: 'Child',
  props: ['title'],
  methods: {
    fn() {
      this.$emit('update:title', 'hi i am child')
    }
  }
}
</script>

<style></style>
